8255_3.asm

WAVE6000编写的常用的程序 包括键盘 通信 数据转换

        org 0000h         ;交通控制灯   
        ajmp main         ;片选/cs接A15 ,AA0接A0,AA1接A1,J3接PC口
        org 001bh
        ajmp serve
        org 0030h
  main: mov tmod,#10h
        mov th1,#3ch
        mov tl1,#0b0h
        mov dptr,#7fffh       ;送控制字
        mov a,#90h            ;A口为输入,B口、C口为输出
        movx @dptr,a
  ll:   mov r4,#14h
        mov r5,#1eh
        setb ea
        setb et1
        setb tr1
        acall change
  ll1:  mov dptr,#7fffh       ;PC7置1,L8亮
        mov a,#0fh
        movx @dptr,a
        mov dptr,#7fffh       ;PC1置1,L1亮
        mov a,#01h
        movx @dptr,a
        mov r0,#08fh
        cjne r5,#00h,ll1
        clr ea
        mov r5,#1eh
        mov dptr,#7fffh       ;PC7置0,L8灭
        mov a,#0eh
        movx @dptr,a
        mov r3,#04h
   ll2: mov dptr,#7fffh       ;PC6置1,l7亮
        mov a,#0dh
        movx @dptr,a
        mov r0,#01h
        acall delay
        mov dptr,#7fffh       ;PC6置0,l7灭
        mov a,#0ch
        movx @dptr,a
        mov r0,#01h
        acall delay
        djnz r3,ll2
        mov dptr,#7fffh       ;PC1置0,L1灭
        mov a,#00h
        movx @dptr,a
        mov r4,#14h
        mov r5,#1eh
        setb ea
        acall change
 ll3:   mov dptr,#7fffh       ;PC5置1,L6亮
        mov a,#0bh
        movx @dptr,a
        mov dptr,#7fffh       ;PC2置1,L3亮
        mov a,#05h
        movx @dptr,a
        mov r0,#08fh
        cjne r5,#00h,ll3
        clr ea
        mov dptr,#7fffh       ;PC2置1,L3灭
        mov a,#04h
        movx @dptr,a
        mov r3,#04h
 ll4:   mov dptr,#7fffh       ;PC1置1,l2亮
        mov a,#03h
        movx @dptr,a
        mov r0,#01h
        acall delay
        mov dptr,#7fffh       ;PC1置0,l2灭
        mov a,#02h
        movx @dptr,a
        mov r0,#01h
        acall delay
        djnz r3,ll4
        mov dptr,#7fffh       ;PC5置1,L6灭
        mov a,#0ah
        movx @dptr,a
        ajmp ll

 serve: push psw
        mov th1,#3ch
        mov tl1,#0b0h
        djnz r4,kk
        mov r4,#14h
        dec r5
        acall change
  kk:   pop psw
        reti
change: mov a,r5
        mov b,#0ah
        div ab
        mov r6,a
        mov a,b
        acall display
        mov a,r6
        acall display
        mov a,#0h
        acall display
        mov a,#0h
        acall display
        ret
display:mov dptr,#tabel
        movc a,@a+dptr
        mov sbuf,a
        jnb ti,$
        clr ti
        ret
delay:  mov r1,#0ffh
  del:   mov r2,#0ffh
        djnz r2,$
        djnz r1,del
        djnz r0,delay
        ret
 tabel:db 0bbh,09h,0eah,6bh,59h,73h,0f3h,0bh,0fbh,7bh